Stapler valve



Aug. 8, 1961 HJ. STARR 2,995,114

' STAPLER VALVE Filed Jan. 29, 1959 2 Sheets-Sheet 1 HENRY J. STARR )WM/2@ Q04/ A T TORNE Y ug- 8, 1961 H. J. STARR 2,995,114

STAPLER VALVE Filed Jan. 29, 1959 2 Sheets-Sheet 2 s M" 4f 50 i ,4% fi H1, @Eg w f, z f L5 L-. M g, ,if 45' /QZ 60 Y afg! 27%/ /44 y s-f- ,A

/f/ F/a 4 L Z7 5496 INVENTOR. HENRY J. STARR A 7' TORNEY nited States Patent* F 2,995,114 STAPLER VALVE Henry J. Starr, 7 Sedgwick Ave., Darien, Conn. Filed Jan. 29, 1959, Ser. No. 789,872 Claims. (Cl. 121-21) This invention relates to new and useful improvements in air valves and more particularly pertains to a control valve for 'an air powered stapler.

It is an important object of the present invention to provide i-n an air powered stapler an air valve having a fast opening action whereby a ow clearance of substantial size is instantaneously provided when the valve is opened.

Another object of the present invention is to provide an improved valve control system for a pneumatic stapler having a trigger mechanism to control the air supply therethrough for driving la staple driver and to exhaust the air upon completion of the staple driving stroke.

Yet another object of Ithe invention is to provide an air powered stapler having a valve action that can be operated with a very light trigger squeeze even though the air supply is under a high pressure.

Still another object of the invention is to provide an improved lair powered stapler having few parts, that is easy to make, and requires little if any maintenance.

Other objects, features and advantages of the present invention will be apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the following drawings in which:

FIG. 1 is an elevational view partly in section of an air driven stapler unit embodying the principles of the present invention;

FIG. 2 is a fragment of the view illustrated in FIG. 1, showing details of the air stapler valve during the initial stage of opening;

FIG. 3 is a fragment of the view illustrated in FIG. l, showing the air stapler valve in its fully opened position;

FIG. 4 is a sectional elevational view showing a modied form of the valve assembly of the invention during the initial stage of opening;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FlG. 6 is a view similar to FIG. 4, but showing the valve assembly in its fully opened position; and

FIG. 7 is a view similar to FIG. 4, but illustrating the manner of exhausting air from the air stapler upon completion of the stapler driving stroke.

Illustrated in FIG. 1 is a stapler unit -10 embodying the principles of the present invention and comprising an assembly of a hand grip portion or handle unit 12 rigidly secured to one end of a body portion or stapler housing generally indicated at 14 and a stapler magazine 16 attached to the other end thereof. The body portion 14 comprises a cylinder 18 provided with a cup-shaped piston 20 which is slidably disposed therein and normally held in its uppermost position by a piston return coil spring 22 positioned between the piston and the lower end of the cylinder.

The upper end of the cylinder 18 is slidably closed by a lock spring and plug 24 norm-ally disposed in abutment with the upper face of the piston 20, there being a chamfered surface 26 on the piston to break the seal between the piston and the plug after air has been admitted into the cylinder. Secured to the piston 20 is a staple driver 28 which drives staples from magazine 16 into the work to be stapled in known manner. Inasmuch as the present' invention does not reside in the specific features of the stapler driver 28 or in the manner in which the staple driving action is accomplished, such will not be shown or described herein.

However, in thisprespect,

ice

reference may be made to my copending application, Serial No. 682,812, iiled September 9, 1957, or my concurrently filed application, Serial No. 789,871, led January 29, 1959.

The handle i12 is provided with a bore 30 which isl internally threaded to receive a complementary threaded pipe or supply line 32 which is connected to a suitable source of compressed air. Contained Within the handle 12 is a pressure chamber 34 communicating at one end with the compressed air line 32 and the other end with a passageway 36 leading into a valve chamber 38 constituted of upper and lower valve cham-ber sections 38a and 38b, respectively.

A valve head 40 adapted to slidably reciprocate in the manner of a piston in the upper valve chamber section 38a is normally maintained in closed relation with respect to the passageway 36 by means of an oil resistant O-ring uid seal =41 such as neoprene, that abuts a sleeve or wall 42 in the lower valve chamber section 3817. A recess or cavity 43 is formed in the upper part of the valve head 40 and provided with a valve opening 44 communicating with the lower section 38b of the valve chamber. A valve element 46 preferably made of neoprene of smaller diameter than said valve head 40 is movable in the valve chamber 'and seats over Valve opening 44 to control the flow of air therethrough. A small diameter compression valve head coil spring 52 ywhich is compressed at one eud against the valve head `40 and at its other end against the closure cap 50^a thereby urging the valve head 40k against the wall 42, into sealing relation therewith. -It -will be recognized by those skilled in the art that other suitable spring arrangements may be employed to fulfill the functions of springs 48 and 52. v

Slidable within a sleeve 5-3 in the lower valve chamber section 3l8a is an elongated operating button 54 which can be operated by `a button head or trigger as desired, a hollowed, semi-cylindrical trigger 56 pivoted about a pin 58 being shown and illustrated herein. Downward pivotal movement of the trigger 56 is limited by body portion 14, as indicated in FIG. l thereby preventing operating button 54 Ifrom falling out of sleeve 53. A stepped shank or neck portion 60 on the button 54 extends into an enlargement of the sleeve forming the sleeve wall 42 and defining lower valve chamber section 38h. Integrally united with the neck portion 6i) and in stepped relation thereto is van elongated stem 62 which is adapted to be loosely receivable through the valve opening 44 in valve head 40. Provision is made at the juncture of the neckY Also provided in the forward end of the handle 12 is a cylinder inlet port or passageway 70 which communicates with the cylinder 18 and the lower valve chamber section 3817. An exhaust port passage 72 cut in the sleeve 53 communicates at one end with the lower valve chamber section 38b when the operating button 54 is in Iits lower or retracted position. The opposite end of exhaust passage 72 terminates at the handle surface and exhausts into thefY `air. The stem 62 is of such length as to provide during upward movement of the button 54 a predetermined clearance between the Afree endof the stem4 and the valve ele` ment l46 to thereby allow the Valve element 46 to be lifted so that air from upper chamber 38av escapes into valve chamber 38h before the ange 64contacts the valve head ber 34 bleeds past the valve head 40-into the upper valve chamber section 38a 'and rapidly builds up the pressurev to act downwardly upon the upper surface of valve head 40 to press the O-ring seal 41 against the sleeve wall 42. Ait the same time, the air from chamber 34 will act upwardly against the annular suuace of the valve head 40 exposed to the chamber air pressure to produce an opposite but smaller force thereon. Referring to FIG. 2, as the trigger 56 is initially squeezed, the free end of the stem v62. is raised through the valve opening 44 into contact with the valve element 46, and the operating button 54 moves toward the upper end of the sleeve 53, thereby blocking the exhaust port 72. Continued depression of the button 54 causes the stern 62 to raise the valve element 46 against the resistance spring 58 and air pressure in upper chamber 38a into the open position. Thereafter, as explained above, the conical flange 64 on the stepped neck portion 60 seats against the lower face of the head valve 40. As soon 'as the valve element 46 is opened, air under pressure in upper valve chamber section 38a passes through the clearance space in valve opening'44 and radial slots 66 into the lower valve chamber section 38h, thereby lowering the pressure on the upper side of the valve head 40. The air then enters the inlet port 70 and the annular space behind the piston dened by the cham-fared surface 26, and break the seal between the top face of the piston 20 and the plug 24` vCoincident with the opening of the valve element 46, and the consequent reduction in air pressure in the upper valve chamber 38a, the relatively larger air pressure from pressure chamber 34 acts upwardly against the annular surface of the valve head 40 and raises the valve head to its open position, as shown in FIG. 3. A plentiful supply of air is then available to pass directly from the passageway 36 through the lower valve chamber 33a and into cylinder inlet port 70 to drive the piston with maximum force. The force of the air pressure lifting the valve head 40 makes the trigger squeeze very light, which is highly desirable.

Upon release of the trigger 56, the compression spring 48 seats the valve element 46, the compression spring 52 aided by the bleeding of air into valve chamber 38a returns the valve head 40 to its starting position thereby closing passageway 36, and the button S4 uncovers the exhaust port 72 thereby venting the lower valve chamber 38b.

Coincident With the uncovering of the exhaust port 72, the piston spring 22 returns the piston 20 to its starting position, venting the air from the stapler cylinder 18.

In the modification shown in FIGS. 4, 5, 6 and 7, a T- shaped stem 62 is carried by the valve element 46, and the stepped neck portion 60 is provided with a sealing gasket 64' instead of a conical ilange 64. In addition, the button 54 has a hollow bore lor exhaust port 7 2.

As the trigger 56 is initially squeezed, the sealing gasket 64' seats against the lower face of the valve head 40', blocking the exhaust port 72 from chamber 38h and raising the stem y62 and the valve element 46 carried thereby inthe manner'shown in FIG. 4. Air under pressure in the upper valve chamber 38a is thereby released through exhaust port 72', enabling the valve head 40 toY be opened as shown in FIG. 6 in substantially the same manner as described in connection with FIG. 3.

Upon release of the trigger 56, the valve element 46 and the valve head 40 both close as described hereinabove, and air is vented from vthe stapler through exhaust port 72".

It lwill be understood that modications and variations may be elected without departing from the spirit and scope of the invention. i

i .What is claimed is:v

1. Anair'valve 'comprising a valve chamber, a valve position, compressed air ows from said port through said valve chamber and said passage, said valve head having a clearance t in said valve chamber suidcient for compressed air from said port to bleed behind said valvev head and urge said valve head into closure position, thereby interrupting the flow of compressed air through said valve chamber and said passage, ran annular surface portion on said valve head exposed to the compressed air in said port and tending to retract said valve head from closure position, and means for reducing the pressure of :the compressed air behind said valve head relative to said chamber, thereby enabling the compressed air in said port acting upon said annular surface portion to retract said valve into open position, said air valve being provided with means for exhausting the air `in said valve chamber and automatically returning said valve head to closure position, said means for reducing the pressure of the compressed air behind said valve having provision for automatically suspending the exhaustion of air from said valve chamber during the ilow of compressed air therethrough.

2. An air valve comprising a valve chamber, a valve .Y head normally slidably movably in said valve chamber from an open position to a closure position against an abutment therein, an air inlet port leading into said valve chamber on one side of said abutment for introducing compressed air into said valve chamber, an air passageV leading away from said valve chamber on the other side of said abutment whereby when said valve head is in open position, compressed air flows from said port through said valve chamber and said passage, said valve head having a ;clearance yiit in said valve chamber sufficient for comby interrupting the flow of compressed air through said valve chamber and said passage, an annular surface portlon on said valve chamber exposed to the compressed air in said port and tending to retract said valve headV from closure position, an opening through said valve head affording communication from behind said valve head to` said valve chamber and said passage, a valve element urged by said spring means into seating position on said opening, an exhaust port in said valve chamber, and an elongated movable button for raising said valve head away from said opening, against the action of said spring means and the air pressure behind said valve head, and automatically closing said exhaust port from said valve chamber, whereby fthe pressure of the compressed air behind said valve head is reduced relative to said valve chamber, said valve head is opened, and compressed air flows from said port through said valve chamber and said passage.

3. An air valve according to claim 2, said exhaust port being a longi-tudinal bore through said button.

4. An air valve according to claim 2, said exhaust port being disposed adjacent said button and adapted to be controlled by the movement of said button therepast.

5. A stapling machine comprising an air cylinder, a piston reciprocably movable therein and driven by comf pressed air, and an -air valve controlling the ow of composition, an abutment in said valve chamber disposed against said valve head, an air inlet port leading into said valve chamber on one side of said abutment for introducingcornpressed air into said valve chamber, an air passage leading away from said valve chamber on the other side of said yabutment whereby when said valve head is in open position, compressed ai-r ows from said port through said valve chamber and said passage, to drive said piston in said cylinder, said valve head having a clearance ii-t in said valve chamber suicient for compressed air from said port to bleed -therepast and urge said valve head to a closure position into engagement with said abutment, thereby interrupting the ow of compressed air through said valve chamber and said passage, an annular surface portion on said valve head in communication with the compressed -air in said port and tending to move said valve head away from Vsaid abutment, and reciprocable means cooperable with said valve head in one direction for reducing the pressure of the compressed air behind said valve head thereby to retract said valve into open position, and operable in the opposite direction to increase the pressure behind said val've head and simultaneously enabling the air yfrom said air cylinder to exhaust during the return stroke of said piston.

References Cited in the le of this patent UNITED STATES PATENTS 205,903 Quinn July 9, 1878 599,462 Schaik Feb. 22, 1898 613,802 Kenney Nov. 8, 1898 851,165 Fernald Apr. 23, 1907 1,374,244 Silvernaie Apr. 12, 1921 1,981,230 Glab` Nov. 20, 1934 2,674,326 Siebens Apr. 6, 1954 2,786,450 Jacobus et al Mar. 26, 1957 2,795,391 Krone et a1. June 11, 1957 2,821,170 Jacobus Ian. 28, 1958 

